Linux kernel vulnerability in CIFS/SMB client affects many distributions and can enable kernel compromise on systems mounting SMB shares.
CVE-2026-97555
Heap overflow in Linux CIFS/SMB client DACL rewrite enabling kernel memory corruption.
Is CVE-2026-97555 being exploited?
Not confirmed. CVE-2026-97555 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-97555?
CVE-2026-97555 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-97555?
Yes. A fix has been recorded for CVE-2026-97555. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-97555 affect?
CVE-2026-97555 affects Linux kernel (cifs/smb client), Hosts mounting CIFS/SMB shares, Servers/desktops using cifs mounts. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-97555?
Apply vendor/upstream kernel patches immediately; avoid untrusted SMB servers.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Kernel heap overflow during SMB DACL rewrite; can cause kernel memory corruption leading to privilege escalation or remote kernel compromise when mounting malicious SMB shares.
Immediate action required
- affected>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < fb736ab4fb8c4fdb8b2f9ccd3a62e03d11549ca1
- affected>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < 7fa84c9ca690643f429ae2709584a47e74b572c9
- affected>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < 2a9aee9ef5622d58d8aafaa3263b3ffe70e2d9dd
- affected>= bc3e9dd9d104ca1b75644eab87b38ce8a924aef4 and < 0ee150794c75bcd0be0e24ff3394f433cbae18cc
- affected5.12
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.